GeForce 825M vs Radeon HD 4790

Intro

Compare all of that to the Radeon HD 4790, which uses a 55 nm design. AMD has clocked the core frequency at 600 MHz. The GDDR5 memory works at a speed of 800 MHz on this model. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

In theory, the Radeon HD 4790 should be much faster than the GeForce 825M overall. (explain)

Radeon HD 4790		102400 MB/sec
GeForce 825M		14400 MB/sec
	Difference: 88000 (611%)

Texel Rate

The Radeon HD 4790 will be quite a bit (about 41%) better at texture filtering than the GeForce 825M. (explain)

Radeon HD 4790		19200 Mtexels/sec
GeForce 825M		13600 Mtexels/sec
	Difference: 5600 (41%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4790 is a better choice, by far. (explain)

Radeon HD 4790		9600 Mpixels/sec
GeForce 825M		6800 Mpixels/sec
	Difference: 2800 (41%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the max amount of information (measured in megabytes per second) that can be transported over the external memory interface in one second. It is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.